The product of the recA gene of Escherichia coli has been implicated as playing a major role in genetic recombination and DNA repair, as well as in the induction of temperate prophages and the induction of mutations. This project will purify the recA protein, study its biochemical properties, and examine the manner its synthesis is regulated. BIBLIOGRAPHIC REFERENCE: McEntee, K., Hesse, J.E. and Epstein, W. (1976) Identification and radiochemical purification of the recA protein of Escherichia coli K-12. Proc. Nat. Acad. Sci., U.S.A. 73:3979-3983.